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05' CRF250 Rebuild

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Hey,

I have on 05' CRF250 that recently siezed up and the crankshaft peeled back so i decided to rebuild the motor myself for fun. I have currently replaced the bottom end and made sure the tranny shifts through its gears. The problem i have right now is that the entire crank has side to side play. I know the rod should have a little but not the crank. I assembled the bottom end completely and still has the play. Followed Clymer to the T, but cannot figure out why the play in the crank. Any help would be great.

Also i have noticed when i put on the Balancer Driven Gear on the Blancer shaft that is does not line up exactly with the Balancer drive gear from the primary assembly. The Balancer driven gear actually sits behind the the balancer drive gear. IS that supposed to be like that? I though they were supposed to be flush.

Thanks

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Once you get it together the rest of the way, the play will be gone. The balance shaft gears don't line up or is it upside down. I can't remember if it will even go, but I think they just don't line up flush like you thing the should.

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Once you get it together the rest of the way, the play will be gone. The balance shaft gears don't line up or is it upside down. I can't remember if it will even go, but I think they just don't line up flush like you thing the should.

So your saying once i put on the flywheel and clutch basket the carnk should have no play anymore? Is it normal to have play when just the bottom end (Cases) are together and torqued tight, but no gears are on yet?

Oh ok perfect. I know its not on backwards because i followed my Clymers.

Thanks for the quick response Charlie.. If anyone else has advise on this please feel free to chime in..

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No, the flywheel won't make a difference. It's on the tapered shaft. It's the drive gear on the other side of the crank that pulls everything into place.

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oh ok... That makes sense. Thank you very much. Was just very weary of putting it all back together with the crank moving back and forth like that..

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Charlie,

thank you you were correct. once i put on the primary gears it tightened right up. Also i got the balancer gears to line up perfect. I never seated the balancer drive gear on the primary all the way into the seal like it was supposed to. now i got my piston in and the build is coming along.

PA110310.jpg

PA110309.jpg

PA110308.jpg

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Is there a like button? I sho nuff like sum motor build pics!

I think it's something that needs to be enabled on your web brouser. I don't see the pictures either but I don't know much about computers. I'm older and that's my excuse.

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I think it's something that needs to be enabled on your web brouser. I don't see the pictures either but I don't know much about computers. I'm older and that's my excuse.

No I see the pics, was trying to be funny and saying that I like to see other guys build pics:thumbsup:

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HAHA.. I got a question... If the Cam looks good do i need to replace it? Also should i replace the cam chain?

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Looks like the clutch basket is pretty notched up... There was an article somewhere that suggested to simply file the surfaces so that they're flush again. I did that, will see if that makes clutch action better.

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Thanks DAKH...

I found a new clutch basket OEM for cheap. It says that it is for an 07 part #06220KRN305, but i was wondering if it fits an 05' as im pretty sure they are interchangeable. the 05' part number is 2210KRN670.

Anyone know?

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Thanks DAKH...

I found a new clutch basket OEM for cheap. It says that it is for an 07 part #06220KRN305, but i was wondering if it fits an 05' as im pretty sure they are interchangeable. the 05' part number is 2210KRN670.

Anyone know?

It will fit.

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Charlie,

So i am buying a new clutch basket because mine is pretty bad, but wondering if i need to replace the clutch plates as well. All the plates were within the thikcness limits and the driver plates were not warped when i checked them. What do you think? Should i also change the hub as well since im changing the basket? Can i just file the basket down instead?

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Charlie,

So i am buying a new clutch basket because mine is pretty bad, but wondering if i need to replace the clutch plates as well. All the plates were within the thikcness limits and the driver plates were not warped when i checked them. What do you think? Should i also change the hub as well since im changing the basket? Can i just file the basket down instead?

As long as the frictions are still within the service limits, you should have no problem re-using them and the steels. You can file the basket and I've seen some pictures of some that were really done nice, but only time will tell how long it's going to last. After you file the grooves out, there's going to be more play in the basket whick in turn lets the frictions move more than normal and technically should groove up faster. I wouldn't be surprised if it didn't lead to a broken friction also. I would definately replace the inner hub with a new one. I think the stock hub is around $50. The reason for replacing the inner hub is for 2 reasons. They wear on the back side where the inner most friction rides and if you look where the steels ride on the hub, you'll find notching there also and the steels hang up just as bad if not worse than the frictions being steel on aluminum. Get some new HD barnett springs to replace the stock springs also. Like $15.

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As long as the frictions are still within the service limits, you should have no problem re-using them and the steels. You can file the basket and I've seen some pictures of some that were really done nice, but only time will tell how long it's going to last. After you file the grooves out, there's going to be more play in the basket whick in turn lets the frictions move more than normal and technically should groove up faster. I wouldn't be surprised if it didn't lead to a broken friction also. I would definately replace the inner hub with a new one. I think the stock hub is around $50. The reason for replacing the inner hub is for 2 reasons. They wear on the back side where the inner most friction rides and if you look where the steels ride on the hub, you'll find notching there also and the steels hang up just as bad if not worse than the frictions being steel on aluminum. Get some new HD barnett springs to replace the stock springs also. Like $15.

Ok... I am going to just bite the bullet and replace the whole clutch assembly. Now on to my next question..

I just did a solvent test on the valves and had no leaking whatsoever on any of the valves. Im assuming that means that my seats and valves are fine.. Should i take out the valves and look at them? Should i just replace the valves with new ones and not worry about new seats since mine is sealed nicely? Or should i just leave what i have and check clearances once back together and go from there? Here are some pictures after i cleaned them up..

PA120306.jpg

PA120309.jpg

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just because they seal doesn't mean they arent beat and will start moving on you. need to at least pull them out, check the shape, and lap them in to get a read on the contact area. there is probably somewhere on the net that shows what a proper seat should look like when lapped in.

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Aren't lapping Ti coated valves a big no-no?

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Don't lap the valve. Not the ti intakes.

I just replaced my intakes. The seat was fine, new valves held a seal with light thumb pressure, local shop popped them in and said the seat didn't need to be cut. How true that is, and if it holds we will see. Got about 5 hours on it with no movement. Its a good idea to cut the seat, but I didn't and seem to be "ok "

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Replacing the intake valves and not having the seats cut is going to shorten the lifespan on the new valves significantly. The valve seat is not going to be uniform to the new valve. Also, the seats are inpregnated with the sand, dirt and particles that have been sucked in through the intake path and embedded themselves into the seats. There's more to it than what most think.

!NEVER LAP A TITANIUM VALVE!

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